1. Field of the Invention
This invention relates to machines for selectively dispensing or vending several types of products of generally cylindrical configuration, such as products in cans or bottles. More particularly, the invention is concerned with providing improved apparatus for accommodating an increased total number of products within a limited available storage space, within the constraints of also accommodating a substantially greater number of at least one preferred product type than of other product types and assuring equal reliability of dispensing operation for all product types. In a still more specific sense, the invention provides product supporting, guiding and releasing means in an improved combination and interrelationships for optimumly apportioning the available space within a given cabinet to satisfy the mentioned constraints within a selective machine handling several product types.
2. Description of the Prior Art
The organization of the various essential elements of product dispensing or vending machines is, in a practical context, influenced by a number of sometimes conflicting considerations, including efficient utilization of the space available for the storage of products to be dispensed, the reliable control over the releasing of individual products from storage upon demand and without vulnerability to either fraudulently induced or mechanical malfunction caused dispensing of more than one product during each dispensing cycle, and providing appropriate means for guiding products during feeding thereof from storage to the product releasing means in manner minimizing vulnerability to jams and preferably utilizing gravity as the sole force required for accomplishing such feeding of products.
As will be apparent, a maximum number of products can normally be stored within a space of given volume by utilizing the latter essentially as a box or hopper with the products emplaced therein in interengaging random fashion. Such hopper approach to the storage of products to be mechanically dispensed, however, has been found highly vulnerable to the creation of jams as the stored products move toward the lower extremity of the hopper during the successive dispensing operations, and it has also proved difficult to provide a form of product releasing mechanism for use at the lower end of a hopper, which is capable of reliably dispensing products stored thereabove in essentially random fashion on a successive individual basis.
Accordingly, over the years, it has become most common to provide some form of product guiding or/and supporting structure within the product storage space available in dispensing or vending machines, for the purpose of preventing the type of jamming problems that arise with open hopper storage, while preferably accomplishing this in manner that requires the interposition within the storage space of a minimum amount of guiding and support structure, which will occupy a minimum portion of the space otherwise available for the storage of the products themselves. Three general types of such product guiding or/and support structure have been commonly employed for the mentioned purpose, namely, vertical partitions or the like spaced from each other within the storage space so as to accommodate the stored products between adjacent pairs thereof in vertical columns of such products, vertical partitions or the like within the storage space, spaced from each other a greater distance than the corresponding horizontal dimension of one product but less than twice such dimension to receive the stored products within the chambers thus presented in an arrangement commonly referred to as a "staggered stack", and a set of superimposed and inclined shelves each adapted to receive a rollable row of products thereon.
Each of such techniques of product storage has spawned the development of product releasing mechanisms especially adapted for utilization with the corresponding product storage arrangement, and each of such product storage techniques and the types of product releasing mechanisms normally utilized therewith is characterized by various advantages or shortcomings dependent upon the particular application involved. Indeed, there is probably less than full unanimity among those skilled in the art as to exactly which type of product storage and releasing arrangement may be best suited for at least certain applications, which has led to proposals for various hybrid forms of apparatus, particularly for use in machines for handling only a single variety of product. Representative illustrations of this would include the Donaldson U.S. Pat. No. 2,399,105, the Holt et al U.S. Pat. No. 2,615,773, the Gale U.S. Pat. No. 2,770,393, the Gale U.S. Pat. No. 3,749,280 and the Patzer et al U.S. Pat. No. 2,877,928, the last-mentioned of which appears to suggest duplication of the arrangement advocated in a manner which might permit extension to a variety selecting operation. In brief, the Donaldson patent employs merging paths between side by side vertical column arrangements of products of the same variety in order to utilize a single product releasing mechanism with a plurality of such columns, thereby overcoming one of the usual disadvantages of vertical column arrangements; the Holt et al patent feeds products of the same variety off the lower ends of inclined shelves into a center zone in which the products tend to arrange themselves in manner seemingly having certain characteristics of a staggered stack but also characteristics of open hopper bulk storage, with product release to be accomplished with a form of staggered stack type releasing mechanism; the Gale U.S. Pat. No. 2,770,393 is similar to Holt et al, but provides means for splitting the products at the lower end of storage into a pair of side by side columns each served by a column type releasing mechanism; the Gale U.S. Pat. No. 3,749,280 advocates essentially open hopper type storage separated at its lower extremity into a pair of staggered stack type chambers each served by a staggered stack type of releasing mechanism; while the Patzer et al patent illustrates inclined shelves feeding products to a vertical column served by a column type product releasing mechanism.
None of the mentioned representative, prior arrangements, however, would appear adaptable or are known to have ever been applied to machines of the modern type in which several varieties of generally cylindrical products, such as canned beverages, must be made available to the consumer on a selective basis. Heretofore, such selective machines have most commonly employed a plurality of side by side staggered stack arrangements of products within corresponding chambers extending throughout the height of the available product storage space and each served by its own selectively operable releasing mechanism. That type of arrangement, has, indeed, proved entirely satisfactory for applications in which it is intended that each of the selectively available varieties of product will be handled by the machine in essentially equal quantities.
It has more recently come to be recognized, however, that the tastes of consumers utilizing a vending machine as a source for products such as canned soft drinks, will not result in statistically equal selection of the various varieties of products offered through a given machine. On the contrary, there is normally one kind of product that will be consumed in quantities several times as great as any other product variety offered through a given machine during any given period of typical operation. In recognition of the biased nature of consumer demand in favor of one or a small number of the product varieties commonly offered through a single dispensing or vending machine, the common prior solution has been simply to dedicate a plurality of the individual staggered stack chambers and associated releasing mechanisms to the dominant or favored products, with the remaining products each served by only a single such chamber and releasing mechanism. Although this approach will permit the product variety preferences of consumers to be in some measure compensated for, such solution has been less than fully satisfactory, because of the difficulty of providing both an adequate number of selections and an appropriate mix of the respective quantities of each of the product varieties to be made available through a particular machine. For example, assuming a machine with six staggered stack chambers of equal height across the width of the machine, each of such chambers may accommodate 162/3 percent of the total products receivable within the product storage space of the machine, which marks the minimum percentage of the storage space to be devoted to any particular product variety with the prior approach, which also would restrict selection of the product percentage to be devoted to a favored variety to multiples of 162/3 percent. A more typical ratio of statistical consumer demand, as actually encountered in practice, however, would require that about 9 or 10 percent of available storage be devoted to each of four secondary products, about 14-15 percent of available storage be devoted to a somewhat preferred secondary product, and that approximately 50 percent of the entire available product storage be devoted to a primary preferred product variety.
Insofar as I am aware, the product storage and releasing techniques heretofore employed or suggested by others have not permitted the efficient design and construction of dispensing or vending machines of the selectable product type based upon realistic conformity with predetermined, desired product mixes between a plurality of varieties of products to be made available through such machine.